Bug 17652: opac-account.pl does not include login branchcode

Bug 17652: opac-account.pl does not include login branchcode

opac-account.pl does not include the login branchcode, whereas the other pages
available to users (opac-user, opac-memberentry, opac-passwd, opac-readingrecord,
opac-suggestions, opac-messaging, opac-shelves, etc.) on login DO provide
the login branchcode. Having the login branchcode available on opac-account.pl
would facilitate customization of the OPAC for individual branches.

To test:
1) Login to the OPAC and open  /cgi-bin/koha/opac-account.pl
2) Inspect the body tag and observe the class attribute does not include
   the login branchcode.
3) Apply the patch.
4) Repeat step 2.
5) Observe that the login branchcode is present.

Signed-off-by: Alex Buckley <alexbuckley@catalyst.net.nz>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>